On May 19, 1920, several mine guards (including Albert and Lee Felts of the notorious Baldwin-Felts Detective Agency), who had been evicting miners from company houses in Mingo County, were ambushed and slaughtered in downtown Matewan. The battle, led by Police Chief Sid Hatfield, also claimed the lives of Matewan's mayor and two miners. Hatfield and his henchmen were trumpeted as champions of the union cause and were acquitted for lack of evidence when brought to trial for the murders. The mine guards sought revenge, however, and Hatfield and an associate were gunned down in broad daylight on the steps of the McDowell County Courthouse the next summer.

All during that troubled summer of 1921 there was violence and unrest in the southern coalfields. Fighting got so bad in Mingo County that Governor Morgan declared martial law there.

To protest the murder of Hatfield and the conditions in Mingo County, the leaders of the union called for a rally at the state capitol on Sunday, August 7, 1921. Mother Jones was invited to speak to the group. She reviled the governor and coal companies in the foulest language and called upon the miners to march into Logan and Mingo counties and set up the union by force.

In Logan County this would mean crushing the power of Sheriff Don Chafin, who was paid by the coal companies to keep out the union. He sustained a force of 300 "special deputies" whose purpose was to watch all incoming roads and railroads and to prevent rallies at the mines. Suspicious characters were jailed without legal recourse and many persons, it was reported, simply disappeared. Don Chafih virtually ruled all aspects of life in Logan County and was hated and feared by the union.

At the capitol rally on the seventh, Mother Jones called for the miners to lynch Chafin and to establish the union at all costs. Frank Keeney, the UMW District 17 president, urged the miners to return to their homes, arm themselves, and wait for a call to action.

Mother Jones and Keeney were calling for the union to gamble its future in one desperate show of force. They realized that if the march was successful and the union could be carried by force into Mingo and Logan counties, the bastion of nonunion labor, then the UMWA would be free to organize any mine in the state.

However, they surely must also have realized that if the armed march was unsuccessful the union would probably be cast out of the southern West Virginia coalfields altogether. It would take years to recover from such a loss.

The call to arms came on August 20, 1921. On that day 600 armed men gathered at Lens Creek, near Marmet in Kanawha County. The area became an armed camp as angry men swarmed in from all parts of southern West Virginia and surrounding areas. Some reportedly came from as far away as Kentucky, Pennsylvania, and Ohio. A few men wore uniforms and helmets, left over from army service in World War I.

Union officials, such as Frank Keeney and Fred Mooney, publicly denied leadership of the mob. Newspaper reporters tried to determine the identity of the leaders but were unsuccessful. Observers reported that the miners organized themselves into small units and elected leaders of these groups, but no one seemed to be in charge of the whole assembly.

By the late afternoon of August 21, 1,500 men had gathered at Lens Creek. Their destination and purpose was kept a secret and reporters and law enforcement officers were turned away. The Charleston Gazette reported that the miners were rumored to be preparing to invade Logan County but no one in authority could be found to verify the rumors. Residents of Charleston were thrown into a panic by rumors that the miners, who were only 10 miles away, were going to attack the capital city.

By the 23rd the number of miners had swollen to between 7,000 and 8,000. Still no leaders emerged publicly. Flu and dysentery invaded the miners' unsanitary camp, and six doctors and eight nurses were brought in to care for the victims.